Formation of stacks of tubes.



0. ZIMMERMANN. FORMATION 0]? STACKS 0P TUBES.

- APPLIOATIOH FILED AUG. 13, 1906. 7

935,723; Patented 0015.5, 1909.

OTTO ZIMMERMANN, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY.

roamn'rron or sTAcKs or TUBES.

Specification of Letters Patent.

Patented Oct. 5, 1909.

Application filed August 13, 1906. SerialNo. 330,456.

To all whom it may concern:

Be it known that I, OTTO ZIMMERMANN, a subject of the German Emperor,.and resident of No. 1 An der Leimfabrik, Ludwigshafen-on-the-Rhine,Germany, have invented certain new and useful Improvements in theFormation of Stacks of Tubes, of which the following is a specification.

This'invention relates to a method whereby a plurality of tubes arrangedside by side are connected tpgether at their ends by a wall thus forminga tube plate.

The tubes, preferably in the form of stacks or groups, are speciallyadapted for use in radiator coolers used on motor vehicles but areequally adapted for heating purposes as will be easily understood. Amethod hitherto proposed for connecting the ends of a plurality of tubesconsists in placing a stack of tubes surrounded or not byan outer.easing into a suitable casting mold with the ends of the tubespreviously stoppered to prevent them being blocked by molten materialwhich is then poured into the mold.

The object of the present invention is to greatly simplify theconnecting together of the ends of a plurality of tubes arranged side byside, for it has been found by the attempts made to do this, that theuse of a casting mold and stoppers for the ends of the tubes isunnecessary.

4 p The invention will now be described with r the profile of the stack.Fig. 3 shows a section on the line A-A of Fig. 1, showing the depth thetubes are dipped into the molten material and which corresponds with thethickness of the tube plate.

Fig. 4 shows a round stack of tubes, the surrounding band being suitablyshaped for thls purpose. Fig. 5 shows a stack of tubes being dipped intothe molten material contained in a flat bottomed vessel. Fig. 6 is amodification showing the preferred form of the invention.

In carrying the invention into effect, a

plurality of tubes, a, of equal length are grouped side by side to thepreferred shape and then gripped or, firmly held together by a suitablesurrounding metal band, I). The stack of tubes thus formed is dippedendwise into the molten soldering material, 0, contained in a suitableflat-bottomed vessel, d, in such a way that the soldering materialenters in the space at thesides, e, and between the tubes to a suitabledepth, f, somewhat as shown in Fig. 3. The bundle of tubes is thencautiously and gently withdrawn from the molten material when it will befound that those portions of the latter filling the interstices betweenthe tubes will remain there, while the metal within the end of each tubewill flow out, owing to the fact that the cohesion between the metal inthe melting vessel and that inside the tubes is greater than thecohesion existing between the wall of the tube and the metal therein,provided that the bore of the tube is not so small that capillary actioncan occur. Thus, the employment of stoppers is needless and it isunnecessary to provide the ends of the tubes with graphite, lime or thelike stoppers. Where tubes of larger bore are required to be soldered inthis manner and thereby the spaces at the sides and also between thetubes and the tion consisting in placing a series of tubes.

of the same length side by side and in direct contact for a part oftheir length, placing a metal band around said tubes so as to, hold themtogether, dipping each end of the group of tubes into molten 'metal andthen withdrawing said group of tubes, said tubes bemg of such a diameterthat the spacesbetween them are of such a size as to retain the metaltherein while said inetal within the tubes Will flow out as the tubesare withdrawn.

2.'A method of forming end plates for band become greater, the ends ofthe tubes "may be enlarged like bell mouths as shown in Flg. 6,

securing the ends of radiator tubes in position, said tubes havingexpanded ends, consisting in arranging a series of tubes of the samelength side byside in direct contact at their ends, placing a metal bandaround said tubes, said band being of the same Width as the length ofthe tubes, dipping each end of expanded ends of the tubes being of sucha 19 diameter that the spaces between them are of such a size as toretain the metal therein While said metal Within the tubes will flow outas tubes are Withdrawn.

OTTO ZIMMERMANN. Witnesses:

VALENTINE MI'JLLER, ERNST HAUCK.

